As the value and use of information continues to increase, individuals and businesses seek additional ways to process and store information. One option available to users is information handling systems. An information handling system generally processes, compiles, stores, and/or communicates information or data for business, personal, or other purposes thereby allowing users to take advantage of the value of the information. Because technology and information handling needs and requirements vary between different users or applications, information handling systems may also vary regarding what information is handled, how the information is handled, how much information is processed, stored, or communicated, and how quickly and efficiently the information may be processed, stored, or communicated. The variations in information handling systems allow for information handling systems to be general or configured for a specific user or specific use such as financial transaction processing, airline reservations, enterprise data storage, or global communications. In addition, information handling systems may include a variety of hardware and software components that may be configured to process, store, and communicate information and may include one or more computer systems, data storage systems, and networking systems.
Information systems include storage systems, such as hard disk drives. Hard disk drives (HDDs) are subject to interference from rotational vibrations (RV) that may be induced by internal components of an information handling system chassis enclosure (e.g., such as cooling fans or other hard disk drives) and from components external to the information handling system chassis enclosure (e.g., such as adjacent information handling systems and other machines). These internal and external components can be sources of vibration/excitation which provide vibrational input to the mechanical operating environment of an information handling system chassis. In some cases, this vibrational input can vary over time as operating conditions change, e.g., due to changes in cooling fan output required by chassis thermal control to maintain acceptable cooling of internal system components despite changes to the ambient temperature in which the chassis resides, the amount of operating stress applied to the central processing unit or other chipset/s or random access memory or activity of HDDs. Adjacent system components such as other HDDs or power supplies can also act as sources that generate varying amounts of vibrational input which can affect the operating environment in which a HDD operates. The path of vibrational wave propagation from such vibrational sources to a HDD enclosed within a chassis is through the mechanical chassis components which are required to support the vibrational sources, electrical components and the HDD that receives the vibrational waves.
RV interference may cause errors in reading and writing operations of a hard disk drive by moving a rotating disk relative to a read/write head of the drive, and thus displacing the head relative to a selected data track on the rotating disk. A conventional process of characterizing hard drive RV performance in enclosures is to measure acceleration outputs in disk drives and chassis locations of interest along with input/output operations per second (IOP) in an attempt to find a correlation between mechanical design parameters-mechanical resonances and IOP. The conventional mechanical design approach is focused in frequency contents to avoid unwanted frequency coupling among resonances of mechanical parts and asynchronous fan frequencies. IOP is measured using a time signal that reflects many different aspects of drive design, including firmware, mechanical, and channel design.
Position error signals (PES) are generated from hard drive servo read back signals, and may be used to correct read and write errors in real time. The PES data indicates how far the read/write heads of the hard drive are moved off-track from the default servo system coordinates at any given instance of time in order to remain in the center of the actual track.